interaction

interaction

Hi All,

I am working on a interaction problem between bolt shank and the bolt hole.
I have a model using shell elements (S4R). I want to create a contact
between the bolt shank and around the bolt hole from the beginning of the
analysis. Namely, I want to make a bearing interaction between these
two materials. As far as I know, there should be a gap (small enough, but
I am not sure what its order must be) between two materials to define a
contact interaction. So;
If a gap is necessary, what is the order of the gap? or How can I define a
contact interaction to create bearing between two members from the beginning
of the analysis?
--
Cuneyt

Re: interaction

Hi Cuneyt,

You do not have to define a gap between the bolt and the hole, zero clearance if perfectly acceptable in Abaqus and will actually aid in the convergence. Do define Contact, you must first define an interaction property with normal and tangential components (at a minimum). I recommend that if you do not know that much about contact to start out with "hard" normal direction properties and "frictionless" tangential properties, then you can modify from there. After that, you define the contact interaction by choosing a master and slave surface and defining how you want to two to "see each other". However, I have never done contact with a shell edge, I always use 3D modeling for contact. It may be possible but if you run into issues, that could be a place to modify your model.

>
> Hi All,
>
> I am working on a interaction problem between bolt shank and the bolt hole.
> I have a model using shell elements (S4R). I want to create a contact
> between the bolt shank and around the bolt hole from the beginning of the
> analysis. Namely, I want to make a bearing interaction between these
> two materials. As far as I know, there should be a gap (small enough, but
> I am not sure what its order must be) between two materials to define a
> contact interaction. So;
> If a gap is necessary, what is the order of the gap? or How can I define a
> contact interaction to create bearing between two members from the beginning
> of the analysis?
> --
> Cuneyt
>
>
> [Non-text portions of this message have been removed]
>

Re: Re: interaction

Hi Dan,

Thank you very much for your suggestion. There is one thing that I am
concerning, if we do not define a gap between two materials, when you
assamble the parts in assembly session ABAQUS would merge all parts. Namely,
bolt shank and hole edge would merge each other. In this case, is it
possible to define a contact interaction between these two materials.

>
>
>
>
> Hi Cuneyt,
>
> You do not have to define a gap between the bolt and the hole, zero
> clearance if perfectly acceptable in Abaqus and will actually aid in the
> convergence. Do define Contact, you must first define an interaction
> property with normal and tangential components (at a minimum). I recommend
> that if you do not know that much about contact to start out with "hard"
> normal direction properties and "frictionless" tangential properties, then
> you can modify from there. After that, you define the contact interaction by
> choosing a master and slave surface and defining how you want to two to "see
> each other". However, I have never done contact with a shell edge, I always
> use 3D modeling for contact. It may be possible but if you run into issues,
> that could be a place to modify your model.
>
> Hope this helps,
> -Dan
>
>
> --- In [hidden email] <Abaqus%40yahoogroups.com>, Cuneyt
> Vatansever <cuneyt.vatansever@...> wrote:
> >
> > Hi All,
> >
> > I am working on a interaction problem between bolt shank and the bolt
> hole.
> > I have a model using shell elements (S4R). I want to create a contact
> > between the bolt shank and around the bolt hole from the beginning of the
> > analysis. Namely, I want to make a bearing interaction between these
> > two materials. As far as I know, there should be a gap (small enough, but
> > I am not sure what its order must be) between two materials to define a
> > contact interaction. So;
> > If a gap is necessary, what is the order of the gap? or How can I define
> a
> > contact interaction to create bearing between two members from the
> beginning
> > of the analysis?
> > --
> > Cuneyt
> >
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>

Re: interaction

Hi Cuneyt,

By default, Abaqus should not be merging your instances into a single part, even if the instances are touching (or even overlapping). It is possible to merge instances into a single part but you have to issue those instructions to CAE. Now there may be some setting or environment variable set that I am unaware of, but what you are describing should not be happening automatically. I'll take a look at your CAE file if you need help figuring out what is going on...let me know.

>
> Hi Dan,
>
> Thank you very much for your suggestion. There is one thing that I am
> concerning, if we do not define a gap between two materials, when you
> assamble the parts in assembly session ABAQUS would merge all parts. Namely,
> bolt shank and hole edge would merge each other. In this case, is it
> possible to define a contact interaction between these two materials.
>
> Cuneyt,
>
> On Thu, Dec 2, 2010 at 7:57 AM, danmilligan2000 <danmilligan@...>wrote:
>
> >
> >
> >
> >
> > Hi Cuneyt,
> >
> > You do not have to define a gap between the bolt and the hole, zero
> > clearance if perfectly acceptable in Abaqus and will actually aid in the
> > convergence. Do define Contact, you must first define an interaction
> > property with normal and tangential components (at a minimum). I recommend
> > that if you do not know that much about contact to start out with "hard"
> > normal direction properties and "frictionless" tangential properties, then
> > you can modify from there. After that, you define the contact interaction by
> > choosing a master and slave surface and defining how you want to two to "see
> > each other". However, I have never done contact with a shell edge, I always
> > use 3D modeling for contact. It may be possible but if you run into issues,
> > that could be a place to modify your model.
> >
> > Hope this helps,
> > -Dan
> >
> >
> > --- In [hidden email] <Abaqus%40yahoogroups.com>, Cuneyt
> > Vatansever <cuneyt.vatansever@> wrote:
> > >
> > > Hi All,
> > >
> > > I am working on a interaction problem between bolt shank and the bolt
> > hole.
> > > I have a model using shell elements (S4R). I want to create a contact
> > > between the bolt shank and around the bolt hole from the beginning of the
> > > analysis. Namely, I want to make a bearing interaction between these
> > > two materials. As far as I know, there should be a gap (small enough, but
> > > I am not sure what its order must be) between two materials to define a
> > > contact interaction. So;
> > > If a gap is necessary, what is the order of the gap? or How can I define
> > a
> > > contact interaction to create bearing between two members from the
> > beginning
> > > of the analysis?
> > > --
> > > Cuneyt
> > >
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >
> >
>
>
>
> --
> Cuneyt VATANSEVER, PhD.
> Research Scholar
> University of Washington
> Civil and Environmental Engineering
> 201 More Hall
> Seattle, Washington
>
>
> [Non-text portions of this message have been removed]
>

Re: interaction

Hey Cuneyt,

When you have a contact between shell elements ABAQUS will take into consideration the thickness of the shells (unless you specify NO THICKNESS parameter when defining your contact).

Gap in contacts is defined with CLEARANCE. If you use a value of, let's say, 0.1 you would tell ABAQUS that the slave can only move 0.1 mm, while 0 clearance will tell ABAQUS that the materials are in contact at the beginning of the analysis and it will keep them together throughout the analysis

On the other hand, you could define *CONTACT INTERFERENCE (although i think of it as obsolete) in which you would tell ABAQUS at what distance from the master it should close the contacts. This should be used only with NO THICKNESS parameter.

So your best bet is CLEARANCE with a chosen value. And remember not to set ADJUST to YES - that would paste the slave nodes over the master ones!

>
>
>
> Hi Cuneyt,
>
> By default, Abaqus should not be merging your instances into a single part, even if the instances are touching (or even overlapping). It is possible to merge instances into a single part but you have to issue those instructions to CAE. Now there may be some setting or environment variable set that I am unaware of, but what you are describing should not be happening automatically. I'll take a look at your CAE file if you need help figuring out what is going on...let me know.
>
> Regards,
> Dan
>
> --- In [hidden email], Cuneyt Vatansever <cuneyt.vatansever@> wrote:
> >
> > Hi Dan,
> >
> > Thank you very much for your suggestion. There is one thing that I am
> > concerning, if we do not define a gap between two materials, when you
> > assamble the parts in assembly session ABAQUS would merge all parts. Namely,
> > bolt shank and hole edge would merge each other. In this case, is it
> > possible to define a contact interaction between these two materials.
> >
> > Cuneyt,
> >
> > On Thu, Dec 2, 2010 at 7:57 AM, danmilligan2000 <danmilligan@>wrote:
> >
> > >
> > >
> > >
> > >
> > > Hi Cuneyt,
> > >
> > > You do not have to define a gap between the bolt and the hole, zero
> > > clearance if perfectly acceptable in Abaqus and will actually aid in the
> > > convergence. Do define Contact, you must first define an interaction
> > > property with normal and tangential components (at a minimum). I recommend
> > > that if you do not know that much about contact to start out with "hard"
> > > normal direction properties and "frictionless" tangential properties, then
> > > you can modify from there. After that, you define the contact interaction by
> > > choosing a master and slave surface and defining how you want to two to "see
> > > each other". However, I have never done contact with a shell edge, I always
> > > use 3D modeling for contact. It may be possible but if you run into issues,
> > > that could be a place to modify your model.
> > >
> > > Hope this helps,
> > > -Dan
> > >
> > >
> > > --- In [hidden email] <Abaqus%40yahoogroups.com>, Cuneyt
> > > Vatansever <cuneyt.vatansever@> wrote:
> > > >
> > > > Hi All,
> > > >
> > > > I am working on a interaction problem between bolt shank and the bolt
> > > hole.
> > > > I have a model using shell elements (S4R). I want to create a contact
> > > > between the bolt shank and around the bolt hole from the beginning of the
> > > > analysis. Namely, I want to make a bearing interaction between these
> > > > two materials. As far as I know, there should be a gap (small enough, but
> > > > I am not sure what its order must be) between two materials to define a
> > > > contact interaction. So;
> > > > If a gap is necessary, what is the order of the gap? or How can I define
> > > a
> > > > contact interaction to create bearing between two members from the
> > > beginning
> > > > of the analysis?
> > > > --
> > > > Cuneyt
> > > >
> > > >
> > > > [Non-text portions of this message have been removed]
> > > >
> > >
> > >
> > >
> >
> >
> >
> > --
> > Cuneyt VATANSEVER, PhD.
> > Research Scholar
> > University of Washington
> > Civil and Environmental Engineering
> > 201 More Hall
> > Seattle, Washington
> >
> >
> > [Non-text portions of this message have been removed]
> >
>